After Jeff and Hugh made their fixes to all the ISI models and restarted them, I did a DAQ restart.
The restart was normal except that h1fw1 did not come back. It had tried to restart its daqd process, and then kernel panic'ed similar to Wednesday evening's crash (VFS count 0). I reset the machine by pressing the front panel RESET button, it all came back normally after that.
We had two more kernel panics after this restart. The sequence is: daqd process dies, monit starts new daqd, process gets as far as opening its log file, kernal panic from put_cred_rcu function.
After second panic, I performed a full power down of h1fw1 and h1ldasgw1. Recovery sequence: power up h1ldasgw1 wait for boot, then manually mount /cds-h1-frames and export as NFS. Then power up h1fw1.